Improperly maintained tires, including tire underinflation, lead to faster wear and increased fuel consumption. A recent study indicates that for each 5% of underinflation (approx 2 psi), translates into 1% of increased fuel consumption. Each litre of fuel consumption causes emission of 2.4 kg of CO2 into the atmosphere. The estimated overall annual cost to Canada's light duty vehicle population due to tire underinflation is almost 643 million additional litres of fuel being consumed, resulting in an additional 1.54 megatonnes of CO2 emission (“The Autosmart Fact Sheet Series”: http://www.betiresmart.ca/pdf/TireCareMaintenance.pdf).
Tubeless tires are currently installed on most light duty vehicles. Generally, when a tubeless tire is installed on an aluminum or alloy wheel, the tire bead is intended to form a seal directly with the wheel to prevent air leakage from the tire. During normal wear, this seal may be disrupted if the wheel is damaged. Aside from physical damage to the wheel due to minor collisions, debris may become lodged between the wheel and the tire bead, compromising the integrity of the airtight seal. In addition, wheels are susceptible to oxidation, particularly in climates where salt is used on the road to mitigate slippery conditions caused by ice and snow. Oxidation of wheel surfaces compromises the seal and permit air to leak from the tire.
The prior art suggests many potential methods to prevent or repair wheel oxidation. For example, when a tire is replaced, the wheel may be polished where it contacts the tire bead to remove surface oxidation. In addition, the wheel may be painted or coated with liquid rubber. Such remedies are effective only for limited periods of time before oxidation again afflicts the wheel surface. Installation of a tube within the tire is generally not considered due to the potential for pinching or puncturing of the tube which may result in a rapid and hazardous loss of air from the tire.
The prior art describes various methods for preventing air leakage from a spoked tube-type wheel to permit a tubeless tire to be installed thereon. These methods include, for example, U.S. Pat. No. 4,108,232, which describes a natural or synthetic rubber shield that is fitted over a spoked tube-type wheel rim to prevent air leakage; and U.S. Pat. No. 6,019,149, which discloses a flat flexible strip for placement against a spoked tube-type wheel to seal the openings in the wheel so a tubeless tire can be installed thereon.
In addition, the prior art includes examples of methods to apply seals to vehicle wheels. For example, U.S. Pat. No. 4,763,392 to Fogal and Taber describes a method of manufacturing rust-proof, leak-proof and air-impervious tire rims. The wheel is cleaned, primed, and a layer of resilient copolymeric material is applied to all exposed surfaces of the wheel by dip-molding. When a tire is installed over the dip-molded wheel, the copolymeric material forms an airtight seal with the tire bead and the copolymeric material tightly adheres to the entire surface of the wheel.
U.S. Pat. No. 4,289,186 to Wilde describes a grooved wheel and a seal member for holding each tire bead under compression to prevent slipping. The seal member is applied to the tire prior to mounting on the wheel.
U.S. Pat. No. 3,956,957 to Nakasaki describes a flexible band for application to a wheel wherein the band includes ribs for engaging grooves in the wheel. Bead stoppers of rigid, lightweight material are anchored to the wheel by bolts, the bead stoppers for pressing the tire bead against the wheel flanges.
U.S. Pat. No. 3,077,219 to Solomon and U.S. Pat. No. 2,787,312 to Servaes each describe the application of two sealing rings for fitting over the wheel to prevent rusting or deformation of the wheel. U.S. Pat. No. 5,820,709 to Matsuda discloses elastic caps for placement over the wheel flanges to prevent leaks.
It is desirable to provide a sealing ring that is lightweight and inexpensive to manufacture, is easily shipped and installed upon a wheel, and provides airtight sealing with the tire bead even when the wheel surface is damaged without a tire bead/metal interface. In particular, there has been a need for an effective sealing ring that is dimensioned to fit over a number of wheels having different widths and that is readily installed on wheels.